This topic contains a solution. Click here to go to the answer

Author Question: Suppose z is a standard normal variable. Find the value of z in the following. a. The area between ... (Read 103 times)

jrubin

  • Hero Member
  • *****
  • Posts: 552
Suppose z is a standard normal variable. Find the value of z in the following.
 a. The area between 0 and z is .4678.
  b. The area to the right of z is .1112.
  c. The area to the left of z is .8554
  d. The area between z and z is .754.
  e. The area to the left of z is .0681.
  f. The area to the right of z is .9803.

Question 2

A random sample of 49 lunch customers was selected at a restaurant. The average amount of time the customers in the sample stayed in the restaurant was 33 minutes. From past experience, it is known that the population standard deviation equals 10 minutes.
 a. Compute the standard error of the mean.
  b. What can be said about the sampling distribution for the average amount of time customers spent in the restaurant? Be sure to explain your answer.
 c. With a .95 probability, what statement can be made about the size of the margin of error?
  d. Construct a 95 confidence interval for the true average amount of time customers spent in the restaurant.
 e. With a .95 probability, what sample size would have to be selected to provide a margin of error of 2.5 minutes or less?



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

mohan

  • Sr. Member
  • ****
  • Posts: 362
Answer to Question 1

a. 1.85
b. 1.22
c. 1.06
d. 1.16
e. 1.49
f. 2.06

Answer to Question 2

a. 1.4286
b. Normal by the central limit theorem
c. There is a .95 probability that the sample mean will provide a margin of error of 2.80 or less.
d. 30.20 to 35.80
e. 62




jrubin

  • Member
  • Posts: 552
Reply 2 on: Jun 24, 2018
Great answer, keep it coming :)


elyse44

  • Member
  • Posts: 319
Reply 3 on: Yesterday
Gracias!

 

Did you know?

ACTH levels are normally highest in the early morning (between 6 and 8 A.M.) and lowest in the evening (between 6 and 11 P.M.). Therefore, a doctor who suspects abnormal levels looks for low ACTH in the morning and high ACTH in the evening.

Did you know?

Critical care patients are twice as likely to receive the wrong medication. Of these errors, 20% are life-threatening, and 42% require additional life-sustaining treatments.

Did you know?

According to the American College of Allergy, Asthma & Immunology, more than 50 million Americans have some kind of food allergy. Food allergies affect between 4 and 6% of children, and 4% of adults, according to the CDC. The most common food allergies include shellfish, peanuts, walnuts, fish, eggs, milk, and soy.

Did you know?

During the twentieth century, a variant of the metric system was used in Russia and France in which the base unit of mass was the tonne. Instead of kilograms, this system used millitonnes (mt).

Did you know?

Cocaine was isolated in 1860 and first used as a local anesthetic in 1884. Its first clinical use was by Sigmund Freud to wean a patient from morphine addiction. The fictional character Sherlock Holmes was supposed to be addicted to cocaine by injection.

For a complete list of videos, visit our video library